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Java > Open Source Codes > org > jfree > util > DefaultConfiguration


1 /* ========================================================================
2  * JCommon : a free general purpose class library for the Java(tm) platform
3  * ========================================================================
4  *
5  * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
6  *
7  * Project Info: http://www.jfree.org/jcommon/index.html
8  *
9  * This library is free software; you can redistribute it and/or modify it
10  * under the terms of the GNU Lesser General Public License as published by
11  * the Free Software Foundation; either version 2.1 of the License, or
12  * (at your option) any later version.
13  *
14  * This library is distributed in the hope that it will be useful, but
15  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
16  * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
17  * License for more details.
18  *
19  * You should have received a copy of the GNU Lesser General Public
20  * License along with this library; if not, write to the Free Software
21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
22  * USA.
23  *
24  * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
25  * in the United States and other countries.]
26  *
27  * -------------------------
28  * DefaultConfiguration.java
29  * -------------------------
30  * (C)opyright 2003, 2004, by Thomas Morgner and Contributors.
31  *
32  * Original Author: Thomas Morgner;
33  * Contributor(s): David Gilbert (for Object Refinery Limited);
34  *
35  * $Id: DefaultConfiguration.java,v 1.5 2006/12/03 15:33:33 taqua Exp $
36  *
37  * Changes
38  * -------
39  * 04.06.2003 : Initial version (TM);
40  *
41  */
42
43 package org.jfree.util;
44
45 import java.util.Collections JavaDoc;
46 import java.util.Enumeration JavaDoc;
47 import java.util.Iterator JavaDoc;
48 import java.util.Properties JavaDoc;
49 import java.util.TreeSet JavaDoc;
50
51 import org.jfree.base.config.ModifiableConfiguration;
52
53 /**
54  * Default configuration.
55  *
56  * @author Thomas Morgner.
57  */
58 public class DefaultConfiguration extends Properties JavaDoc
59     implements ModifiableConfiguration
60 {
61
62   /**
63    * Creates an empty property list with no default values.
64    */
65   public DefaultConfiguration()
66   {
67     super();
68   }
69
70   /**
71    * Returns the configuration property with the specified key.
72    *
73    * @param key the property key.
74    * @return the property value.
75    */
76   public String JavaDoc getConfigProperty(final String JavaDoc key)
77   {
78     return getProperty(key);
79   }
80
81   /**
82    * Returns the configuration property with the specified key (or the
83    * specified default value if there is no such property).
84    * <p/>
85    * If the property is not defined in this configuration, the code will
86    * lookup the property in the parent configuration.
87    *
88    * @param key the property key.
89    * @param defaultValue the default value.
90    * @return the property value.
91    */
92   public String JavaDoc getConfigProperty(final String JavaDoc key, final String JavaDoc defaultValue)
93   {
94     return getProperty(key, defaultValue);
95   }
96
97   /**
98    * Searches all property keys that start with a given prefix.
99    *
100    * @param prefix the prefix that all selected property keys should share
101    * @return the properties as iterator.
102    */
103   public Iterator JavaDoc findPropertyKeys(final String JavaDoc prefix)
104   {
105     final TreeSet JavaDoc collector = new TreeSet JavaDoc();
106     final Enumeration JavaDoc enum1 = keys();
107     while (enum1.hasMoreElements())
108     {
109       final String JavaDoc key = (String JavaDoc) enum1.nextElement();
110       if (key.startsWith(prefix))
111       {
112         if (collector.contains(key) == false)
113         {
114           collector.add(key);
115         }
116       }
117     }
118     return Collections.unmodifiableSet(collector).iterator();
119   }
120
121   public Enumeration JavaDoc getConfigProperties()
122   {
123     return keys();
124   }
125
126   /**
127    * Sets the value of a configuration property.
128    *
129    * @param key the property key.
130    * @param value the property value.
131    */
132   public void setConfigProperty(final String JavaDoc key, final String JavaDoc value)
133   {
134     if (value == null)
135     {
136       remove(key);
137     }
138     else
139     {
140       setProperty(key, value);
141     }
142   }
143 }
144
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